Biomechanical Stability of Diaphyseal Ulnar Shaft Fractures and Ulnar Shortening Osteotomies After Fixation.

BACKGROUND: To determine the amount of micromotion during forearm rotation after diaphyseal ulnar shaft fracture or osteotomy. METHODS: This was a biomechanical study using 7 paired-matched cadavers. The upper extremity was mounted in a custom rig and the forearm brought through full pronation and supination. A Hall effect sensor was placed at the fracture ends to measure micromotion for all tested conditions. There were 4 conditions tested: (1) intact ulnar shaft with plate to act as a control; (2) transverse fracture/osteotomy without stabilization; (3) fracture/osteotomy with cortical apposition stabilized with plate fixation; and (4) 50% comminuted fracture stabilized with plate. RESULTS: There was a significantly greater amount of fracture site motion in the fracture/osteotomy model without stabilization compared with all other tested conditions (P < .001, .0001, .0003, respectively). The fracture/osteotomy site with cortical apposition and the comminuted fracture models showed no statistically significant differences in the amount of micromotion compared with each another (P = .952) or compared with the intact ulnar shaft (P = .997, .889, respectively). CONCLUSIONS: There was no significant difference in the amount of motion between an intact ulnar shaft, an ulnar shaft fracture with cortical apposition stabilized with a plate, and a plated comminuted fracture. These findings may help surgeons decide on their type of postoperative immobilization in the setting of isolated ulnar shaft fractures or ulnar shaft osteotomies stabilized with plate fixation.

Do Computerized Tomography Scans Change Management in Carpometacarpal Dislocations and Fracture-Dislocations?

BACKGROUND: Concomitant carpal injuries with dislocations and fracture-dislocations of the carpometacarpal joints (CMCD/FD) are often hard to see on plain radiographs, making advanced imaging a useful diagnostic adjunct. We aim to: (1) characterize bony injury patterns with CMCD/FD; and (2) determine the frequency that preoperative computed tomography (CT) scans change surgical management. METHODS: A retrospective review was performed of patients who underwent operative fixation of CMCD/FD from 2006 to 2021. X-ray and CT scan diagnoses were reviewed and correlated to intraoperative findings and procedures performed. Statistical analyses were performed to evaluate the frequency in which CT scans changed management and the frequency of new intraoperative diagnoses. RESULTS: Seventy-five patients were identified. All patients had a preoperative x-ray, and 27 patients (36%) additionally had a CT scan. Patients who sustained high-velocity trauma were significantly more likely to obtain a CT scan than patients with low-velocity trauma (P = .019); however, the number of additional diagnoses was not significantly associated with trauma velocity (P = .35). Computed tomography scans significantly increased the number of diagnoses (P < .001) and changed operative management in 58% of cases. Six of the 48 patients (12.5%) that did not receive a CT scan had new intraoperative diagnoses, which changed the procedure for five of these patients. New intraoperative diagnoses were identified significantly more when patients did not have a CT scan (P = .04). CONCLUSIONS: Obtaining a CT scan in CMCD/FD patients changed the patient's diagnosis at a significant rate and changed operative management roughly half of the time. The authors recommend routine CT scans be obtained in patients with CMCD/FD.

The Effect of 3rd Carpometacarpal Arthrodesis in the Outcomes of Total Wrist Fusion Using Modern Plate Technology.

Background The inclusion of the third carpometacarpal (CMC) joint in the fusion mass in total wrist fusion (TWF) remains controversial. Our goal was to evaluate the clinical outcomes and effects of third CMC joint arthrodesis compared with bridging the CMC joint during TWF. A retrospective chart review was performed. Outcomes assessed included hardware loosening, hardware failure, symptomatic hardware necessitating removal, and need for revision arthrodesis. Case Description/Literature Review We found that concomitant third CMC joint arthrodesis was associated with a significantly reduced rate of radiocarpal and midcarpal joint nonunion, hardware loosening, and symptomatic hardware removal when compared to bridging of the CMC joint. There was no significant difference in hardware failure rates or the need for revision arthrodesis. Clinical Relevance When using a contoured dorsal spanning plate, concomitant CMC joint arthrodesis should be considered during TWF to mitigate against hardware loosening and symptomatic hardware. Level of Evidence Level IV.

Diagnosis of a Rare Flexor Tendon Entrapment Using 3D CT Imaging Techniques.

Flexor tendon entrapments as a result of fractures or dislocations in the upper extremity are rare. Diagnosis by clinical examination is not always possible, and imaging such as magnetic resonance imaging and ultrasound is often obtained. These modalities have the disadvantages of reduced sensitivity or increased cost and time, respectively. We present a unique case of a triquetral fracture and pisiform dislocation causing index finger flexor digitorum profundus (FDP-I) entrapment that was diagnosed preoperatively with computed tomography (CT) imaging with 3-dimensional (3D) volume rendering. A 30-year-old man presented in delayed fashion 4 weeks after a dune buggy accident. Among other injuries noted on examination, his index finger was held in flexion and unable to be passively extended. The CT source images showed dislocation and interposition of the FDP-I tendon within a fracture-dislocation of the triquetrum and pisiform. Postprocessed 3D volume renderings obtained from the CT source images confirmed this finding. The patient underwent operative intervention, where FDP-I entrapment between the triquetral fracture fragments and the dislocated pisiform was confirmed and released. Practitioners should be aware of this injury pattern and evolving advanced CT techniques which may be used to aid in soft-tissue diagnoses and obviate the need for additional advanced imaging.

Wrist Arthroscopy Using the 2R Portal: Is It Safer Than the 1,2 Portal?

BACKGROUD: The purpose of this study was to compare the 1,2 with a novel 2R portal in terms of proximity to critical structures. METHODS: Wrist arthroscopy was performed on 8 fresh frozen cadavers via the 1,2 and 2R portals. External anatomy was then dissected under loupe magnification. The closest distance between the portals and surrounding anatomical structures was measured in millimeters using digital calipers. RESULTS: The 1,2 portal was significantly closer to radial artery and first extensor compartment tendons than the 2R portal. The radial artery was on average 1.32 mm from the 1-2 portal and 14.25 mm from the 2R portal. The 2R portal was significantly closer to the second and third extensor compartment tendons. The closest branch of the superficial branch of the radial nerve (SBRN) was on average 2.04 mm from the 1-2 portal and 7.59 mm from the 2R portal, but this was not statistically significant. CONCLUSIONS: We advocate using the 2R portal preferentially to the 1,2 portal when treating radial sided wrist pathology to decrease the risk of iatrogenic radial artery and SBRN injury.

Comparison of Patient Perception and Satisfaction of Face-to-Face Versus Telemedicine Encounters in Hand Surgery.

BACKGROUND: The coronavirus disease 2019 (COVID-19) surge has enabled the widespread usage of telemedicine (TM) and presents a unique opportunity to determine the hand surgery patients' perception of care using validated patient satisfaction scores. METHODS: Electronic surveys were distributed to patients aged 18 years and older who underwent a video TM encounter with a single surgeon at an academic medical center during the initial COVID-19 surge (March 23 to October 22, 2020). The study-specific questions were derived from the Press Ganey (PG) Medical Practice TM Survey and compared with institutional PG Outpatient Medical Practice Survey data. Three cohorts were defined: pre-COVID face-to-face, post-COVID TM, and post-COVID face-to-face. RESULTS: Thirty of 65 TM patients (46.2%) responded. No differences in sex, age, or visit type were identified between cohorts. The TM cohort was more likely to live greater than 300 miles from the institution. Median response for all cohorts for the PG care provider and overall experience responses were "very good," and no differences were identified between cohorts. Patient satisfaction with their TM experience was high with median satisfaction scores for arranging and connecting to a TM visit, talking with the provider over a video connection, and having the provider understand the clinical problem were "very good." Patients in the TM cohort reported no difference in preference for face-to-face or TM visits. CONCLUSIONS: Patients are satisfied with TM as a substitute for face-to-face visits suggesting that TM can possibly be used to deliver comparable patient experience for hand surgery encounters.

Does Proximal Row Carpectomy Improve Union in Wrist Arthrodesis? A Retrospective Cohort Study.

Background Some surgeons advocate for concomitant proximal row carpectomy (PRC) with total wrist arthrodesis (TWA), though there are limited data to support or oppose this view. Questions/Purposes Does concomitant PRC improve rates of union, revision, hardware loosening, hardware failure, and hardware removal in TWA? Patients and Methods A retrospective cohort study of patients who underwent TWA with and without concomitant PRC between January 2008 and December 2018 was undertaken. Patients were included if they underwent TWA using a dorsal spanning plate. Patients were excluded if they underwent partial wrist arthrodesis, revision TWA, or TWA with nondorsal spanning plate fixation. Results A total of 183 wrists in 180 patients were included in the study, 96 (52.5%) in the TWA only and 87 (47.5%) in the TWA + PRC groups. Median clinical and radiographic follow-up was 18.0 months (3.0-133.0 months) in the TWA + PRC group and 18.5 months (2.0-126.0 months) in the TWA only group ( p = 0.907). No difference in nonunion (TWA + PRC: 13/87 [14.9%], TWA only: 18/96 [18.8%], odds ratio: 0.76, p = 0.494), revision (TWA + PRC: 5/87 [5.75%], TWA only: 8/96 [8.33%], hazard ratio [HR]: 0.73, p = 0.586), loosening (TWA + PRC: 4/87 [4.60%], TWA only: 6/96 [6.25%], HR: 0.74, p = 0.646), failure (TWA + PRC: 5/87 [5.75%], TWA only: 4/96 [4.17%], HR: 1.55, p = 0.530), and removal (TWA + PRC: 12/87 [13.8%], TWA only: 16/96 [16.7%], HR: 0.84, p = 0.634) were identified. Conclusion Concomitant PRC might not improve rates of union or diminish complications in patient undergoing TWA. The role of PRC and the rationale for its use in TWA need to be individualized and discussed with patients prior to surgery. Level of Evidence This is a Level IV, therapeutic study.

Factors Impacting the Success of Free Functioning Gracilis Muscle Transfer for Elbow Flexion in Brachial Plexus Reconstruction.

BACKGROUND: Free functioning muscle transfer is a reconstructive option to restore elbow flexion in brachial plexus injuries. The authors determined the impact of body mass index, age, and location of distal tendon attachment on elbow flexion strength after free functioning muscle transfer in traumatic brachial plexus injury patients. METHODS: A retrospective review of patients who underwent free functioning muscle transfer for elbow flexion as part of their brachial plexus injury reconstruction with a minimum 2-year follow-up were evaluated. Outcomes assessed included elbow flexion strength (British Medical Research Council grade) and change in Disabilities of the Arm, Shoulder and Hand questionnaire and visual analogue scale pain scores. RESULTS: One hundred six patients met inclusion criteria. The average age was 32 years, and the average body mass index was 27.1 kg/m2; 56.5 percent of patients achieved M3 or greater muscle grade using the authors' strict modification of the British Medical Research Council scale. Disabilities of the Arm, Shoulder and Hand questionnaire scores improved from 45.7 to 38.8 (p < 0.05). Visual analogue scale pain scores decreased, but this trend did not obtain significance. Age and body mass index both had a significant negative impact on final free functioning muscle transfer grade (p < 0.05). Use of a distal tendon insertion led to improved muscle grade outcomes, with targeting of wrist extension being superior to finger flexion (p < 0.05). Simultaneous musculocutaneous nerve grafting did not significantly alter final elbow flexion strength. CONCLUSIONS: Increasing age and body mass index both imparted a deleterious effect on free functioning muscle transfer muscle grade. Distal muscle targets had better strength outcomes than when the biceps tendon was used. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Preoperative Antibiotics Influence Culture Yield in the Treatment of Hand, Wrist, and Forearm Infections.

When treating upper-extremity infections, clinicians frequently must decide whether to initiate antibiotics or delay them with the goal of optimizing culture yield at the time of surgical debridement. The purpose of this study was to determine whether the administration of preoperative antibiotics affects intraoperative culture yield and whether there is a "safe" interval prior to culture acquisition within which antibiotics can be administered without affecting culture yield. Methods: We conducted a retrospective review of 470 consecutive patients who underwent debridement for a presumed acute infection of the hand, wrist, or forearm at a single tertiary care center between January 2015 and May 2020. Data including patient demographics, mechanism of infection and affected body part(s), and details of antibiotic administration, including type and timing with respect to culture acquisition, were collected. Results: Three hundred and forty-one patients (73%) received preoperative antibiotics prior to debridement and culture acquisition. The rate of positive cultures among patients who received preoperative antibiotics was 81% compared with 95% among patients who did not receive preoperative antibiotics (p < 0.01; odds ratio, 4.73). Even a single dose of antibiotics imparted a significantly increased risk of obtaining negative intraoperative cultures, and an incremental increase in the likelihood of obtaining negative cultures was seen with each preoperative dose given up to 7 doses. We did not identify a "safe" interval of time between antibiotic administration and culture acquisition such that culture yield was not affected. Conclusions: Patients who received preoperative antibiotics for the treatment of upper-extremity infections were approximately 5 times more likely to have negative cultures at the time of debridement than those who did not receive preoperative antibiotics. This effect persisted regardless of the number of doses given or the interval between antibiotic administration and culture acquisition. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Relocating the C5 nerve stump in C5 nerve grafting to prevent iatrogenic phrenic nerve injury.

BACKGROUND: Exploration and grafting of the brachial plexus remains the gold standard for post-ganglionic brachial plexus injuries that present within an acceptable time frame from injury. The most common nerves available for grafting include C5 and C6. During the surgical exposure of C5 and C6, the phrenic nerve is anatomically anterior to the cervical spinal nerves, making it vulnerable to injury while performing the dissection and nerve stump to graft coaptation. We describe a novel technique that protects the phrenic nerve from injury during supraclavicular brachial plexus exposure and grafting of C5 or upper trunk ruptures or neuromas in-continuity. METHODS: A 4-step technique is illustrated: (1) The normal anatomic relationships of the phrenic nerve anterior to C5 is displayed in the face of the traumatic scarring. (2) The C5 spinal nerve stump is then transposed from its anatomic position posterior to the phrenic nerve to an anterior position. (3) The C5 stump is then moved medially for retrograde neurolysis of C5 from its phrenic nerve contribution. The graft coaptation to C5 is performed in this medial position, which minimizes retraction of the phrenic nerve. (4) The normal anatomic relationship of the phrenic nerve and the C5 nerve graft is restored. RESULTS: We have been routinely relocating the C5 spinal nerve stump around the phrenic nerve for the past 10 years. We have experienced no adverse respiratory events. CONCLUSION: This technique facilitates surgical exposure and prevents iatrogenic injury on the phrenic nerve during nerve reconstruction.

Reconstruction of Congenital Sternal Cleft: A Systematic Review of the Literature.

INTRODUCTION: Sternal cleft (SC) is a rare congenital deformity that results from failure of sternal bar fusion. Sternal cleft can be categorized as superior partial, inferior partial, or complete. Each form of SC can present as an isolated defect or in association with other congenital deformities, which presents a unique challenge for reconstructive surgeons. In our systematic review, we aim to summarize the published experience on repair of SCs and present a pragmatic approach to help guide reconstructive planning. METHODS: A systematic review was performed to identify all reported SC cases in literature that underwent sternal reconstruction. RESULTS: Seventy-one studies were identified from 1970 to 2019, which included a total of 115 patients. Superior partial SC was the most common SC variant, accounting for 65.2% (75/115) of all reported cases. There were 31 cases of complete SC (27.0%) and 9 cases (7.8%) of inferior partial SC; 49.6% of the patients (57/115) in our review had isolated SC without any other congenital deformities. Sixty-seven patients (60.3%) were treated with primary closure, with or without secondary maneuvers, such as chondrotomies, cartilage resection, or periosteal flaps. Alternative methods included interposition grafts, with autologous rib graft in 18 patients (15.8%), permanent mesh in 8 patients (7.0%), acellular dermal matrix in 5 patients (4.4%), sternal plate flap in 5 patients (4.4%), and nonthoracic autologous bone grafts in 4 patients (3.5%). CONCLUSIONS: Our review supports that primary closure should be attempted regardless of patient age. For wider sternal gap, reconstruction with an autologous local graft or flap should be considered. When the patient does not have sufficient autologous tissue for a successful sternal reconstruction, alloplastic or allograft interposition options are a reasonable choice.

Morbidity of Nerve Transfers for Brachial Plexus Birth Injury: A Systematic Review.

BACKGROUND: The purpose of this article is to systematically review the peer-reviewed literature on the morbidity of nerve transfers performed in patients with brachial plexus birth injury (BPBI). Nerve transfers for restoration of function in patients with BPBI that fail nonoperative management are increasing in popularity. However, relatively little attention has been paid to the morbidity of these transfers in the growing patient. The authors systematically review the current literature regarding donor site morbidity following nerve transfer for BPBI. METHODS: A systematic review of the Medline and EMBASE databases was conducted through February 2020. Primary research articles written in English and reporting donor site morbidity after nerve transfer for BPBI were included for review. RESULTS: Thirty-six articles met inclusion criteria, all of which were retrospective reviews or case reports. There was great heterogeneity in outcomes assessed. With 5 year or less follow-up, all transfers were relatively well tolerated with the exception of the hypoglossal nerve transfer. CONCLUSION: Nerve transfers are a well-recognized treatment strategy for patients with BPBI and have an acceptable risk profile in the short term. Full hypoglossal nerve transfers for BPBI are of historical interest. Donor site morbidity is grossly underreported. This review highlights the need for more objective and systematic reporting of donor site outcomes, and the need for longer term follow-up in these patients. LEVEL OF EVIDENCE: Systematic review. Level III-therapeutic.

Dog Bites in the United States from 1971 to 2018: A Systematic Review of the Peer-Reviewed Literature.

BACKGROUND: Surgical specialists in plastic, head and neck, hand, trauma surgery, and emergency medicine physicians bear the burden of treating the most serious injuries caused by animals. Most of these incidents result from an attack by a known dog, and breed has been proposed, but not proven, to be a controllable factor. The authors summarize the peer-reviewed literature on dog bites in the United States, specifically as related to the breeds implicated. METHODS: A systematic review of all peer-reviewed publications reporting on dog bites in the United States was performed. MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Library searches were conducted through May 8, 2018, for studies from the United States implicating a specific dog breed as responsible. RESULTS: Forty-one articles met inclusion criteria, the majority of which were single-institution retrospective reviews. Main outcomes were any dog bite reported in the peer-reviewed literature where a specific breed was implicated. Secondary measures included dog bites reported in areas where breed-specific legislation was enacted. The most common pure breed identified was German Shepherd, followed by Pit Bull-type breeds (i.e., American Staffordshire Terrier, American Pit Bull Terrier, Staffordshire Bull Terrier, American Bully), Labrador, Collie, and Rottweiler, respectively. Pit bull-type and German Shepherd breeds are consistently implicated for causing the most serious injuries to patients in the United States across heterogeneous populations, and this remained consistent across multiple decades. CONCLUSIONS: The authors' results indicate that German Shepherd and Pit Bull-type breeds account for the largest subset of pure breeds implicated in severe dog bites inflicted on humans in the medical literature. The role and complexity of mentioning breed in relation to human injuries are also discussed.

Maintained Hand Perfusion in the Setting of Radial and Ulnar Artery Transections: A Report of 2 Cases.

CASE: Two otherwise healthy male patients presented with lacerations to the volar distal forearm. Both patients had capillary refill at the fingertips and intact Doppler signals of the palmar arch. Computed tomography angiography revealed cessation of flow in the major forearm arteries at the level of the lacerations, with distal reconstitution from the anterior interosseous artery in both cases and from a branch off the ulnar artery in 1 case. The patients underwent operative exploration, where complete transections of the radial and ulnar arteries were found and repaired. CONCLUSIONS: In patients without arterial disease, contributions from minor forearm arteries can be sufficient for hand perfusion in the setting of radial and ulnar artery transection.

Comparison of wound strength, histologic, and aesthetic outcomes after microsurgical versus conventional skin closure in a rat model.

The purpose of this study was to compare the healing, strength, and cosmetic outcome of linear incisions after repair with the naked eye, surgical loupes, or a surgical microscope. Two parallel incisions were made on the dorsal skin of Sprague-Dawley rats (n = 36) and the rats randomized into four groups. A single surgeon repaired the incisions using 5-0 poliglecaprone in a running subcuticular pattern using the naked eye (Group I), surgical loupes with 2.5× magnification (Group II), surgical microscope with 5-10× magnification (Group III), and 6-0 poliglecaprone with a surgical microscope (Group IV). Rats were sacrificed at 1, 3, and 6 weeks. At each time point, the tensile strength of each closure was assessed. Macroscopic outcomes were evaluated using the Vancouver Scar Scale (VSS) and histology assessed by a blinded observer. Microscope closure took significantly longer than closure with the naked eye (p < 0.05). There was no significant difference in tensile strength or VSS ratings between the closure methods at any of the time points. On histopathologic analysis, there were a greater number of inflammatory cells and fibroblasts in the 6-0 microscope closure group versus the naked eye closure group at week 3 (p ≤ 0.05). In conclusion, wound repair under magnification did not yield a significant difference in cosmesis or wound tensile strength, but did increase operative time. Moreover, there was a trend toward increased inflammation with microscope-assisted closures, perhaps due to the increased suture burden.

Impact of Design on Force between Flexor Tendons and Distal Radius Volar Plates.

Background Flexor tendon injury is a rare but serious complication of distal radius volar plating. Purpose This study aims to determine whether the design of distal radius volar plates impacts the amount of force exerted on the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendons when the plates are placed proximal and distal to the watershed line. Methods Three commercially available plates were applied to 10 fresh, matched-pair upper extremity specimens. Cyclical loading was applied to the tendons, and the force generated between tendon and plate was measured. Linear mixed effect models were used to evaluate differences in maximum and mean forces by plate position, plate design, and the interaction between position and design. Results Forces on the tendons differed significantly by position but not plate design. For the FPL tendon, the average maximum force with a plate in Soong's grade 2 was 4.50 (95% confidence interval [CI]: 2.8-7.3) times higher than when the plate was in a Soong's grade 0 placement, and 4.63 (95% CI: 2.82-7.61) times higher for the FDP tendon. While not statistically significant, lower observed force values with thinner plates when plates were placed distal to the watershed line suggest that that plate thickness could also be a critical plate characteristic for distally placed plates. Conclusion Despite differences in plate design, the main determinant of plate prominence and therefore flexor tendon injury potential is placement in relation to the watershed line. Clinical Relevance This study may help to guide surgeon implant selection and volar plate design.

Spontaneous Radial Nerve Palsy due to an Unrecognized Myofibroma: A Case Report.

CASE: A 33-year-old woman presented with a six-month history of spontaneous radial nerve palsy and no identified lesion on imaging. She underwent operative exploration where an hourglass deformity was seen and resected. Pathology returned as a rare tumor, a myofibroma. The patient regained full radial nerve function. CONCLUSIONS: A trial of observation is often indicated in the cases of isolated nerve palsy where anatomic lesions have been eliminated. This case highlights that imaging studies can miss a tumor involving nerve and that painless, spontaneous nerve palsy may be a time where early surgical intervention offers a better chance of recovery.

Subungual Tumors: An Algorithmic Approach.

The presentation of benign and malignant subungual tumors often follows a final common pathway of nonspecific nail deformity; as such, delays in diagnosis are common. Therefore, it is imperative to have a high degree of suspicion for malignant lesions and an organized approach to subungual tumors. To that end, we present a diagnostic algorithm encompassing the most common benign and malignant subungual tumors, along with a summary of the presentation, imaging, and treatment of these lesions.

Using a kidney pump to perfuse a free filet flap for reconstruction after hemipelvectomy: A case report.

Long ischemia times adversely affect free flap survival, and large muscle flaps are particularly vulnerable. Hypothermic machine perfusion (HMP) is a well-established method of organ preservation, and recent literature has detailed the use of HMP to extend free flap ischemia times, predominantly in the laboratory setting. One limitation in the study and adoption of free flap HMP has been the availability of standardized perfusion machinery, as thus far institutions have built their own devices. We present a case of a 75-year-old woman with dedifferentiated chondrosarcoma of her right proximal femur. She underwent a "spare parts" surgery using a filet flap from her lower leg. Due to an obligate long ischemia time between flap harvest and revascularization, a kidney transplant perfusion pump was used to flush and cool the flap. After completion of the disarticulation, free tissue transfer proceeded successfully. The patient had an uncomplicated post-operative course until developing a local recurrence at three months post-resection. We believe that the perfusion technology already created for solid organ transplant will have expanding indications in the future of free tissue transfer and limb replantation.

Fat Graft Safety after Oncologic Surgery: Addressing the Contradiction between In Vitro and Clinical Studies.

BACKGROUND: The authors investigate the in vitro and in vivo interaction of human breast cancer cells and human adipose-derived stem cells to address the controversy on the safety of postmastectomy fat grafting. METHODS: The authors co-cultured human adipose-derived stem cells and MDA-MB-231 breast cancer cells in an in vitro cell migration assay to examine the migration of breast cancer cells. In the in vivo arm, the authors injected breast cancer cells (group I), human breast cancer cells plus human adipose-derived stem cells (group II), human breast cancer cells plus human fat graft (group III), and human breast cancer cells plus human fat graft plus human adipose-derived stem cells (group IV) to the mammary fat pads of female nude mice (n = 20). The authors examined the tumors, livers, and lungs histologically after 2 weeks. RESULTS: Migration of breast cancer cells increased significantly when co-cultured with adipose-derived stem cells (p < 0.05). The tumor growth rate in group IV was significantly higher than in groups I and II (p < 0.05). The tumor growth rate in group III was also higher than in groups I and II, but this difference was not statistically significant (p > 0.05). Histologically, there was no liver/lung metastasis at the end of 2 weeks. The vascular density in the tumors from group IV was significantly higher than in other groups (p < 0.01). CONCLUSION: The injection of breast cancer cells, fat graft, and adipose-derived stem cells together increases breast cancer xenograft growth rates significantly.